Work Energy And Power Question 239
Question: A body starts from rest and acquires a velocity V in time T. The work done on the body in time t will be proportional to
Options:
A) $ \frac{V}{T}t $
B) $ \frac{V^{2}}{T}t^{2} $
C) $ \frac{V^{2}}{T^{2}}t $
D) $ \frac{V^{2}}{T^{2}}t^{2} $
Show Answer
Answer:
Correct Answer: D
Solution:
[d] Work done on the body is gain in the kinetic energy.
Acceleration of the body is $ a=V/T $ .
Velocity acquired in time t is $ v=at =\frac{V}{T}t $ K.E. acquired $ \propto v^{2} $ . T
hat is work done $ \propto \frac{V^{2}t^{2}}{T^{2}} $
